Can't have a custom type be the input to a controller action

Nobody has claimed this yet.

With the following controller:

```go
package route171

import (
"errors"
"strings"
)

type Controller struct {
// Dependencies...
}

type Email string

func (email Email) Validate() error {
if !strings.Contains(string(email), "@") {
return errors.New("Not a valid email.")
}
return nil
}

func (c *Controller) Index(email Email) []string {
return []string{}
}
```

There is the following error:

```
genfs: error generating "bud/internal/app/controller/controller.go". controller: unable to load: controller: unable to find param definition for Email. parser: unable to find declaration for "Email" in "route171"
exit status 1
```

This came up when I was working on issue #171

I'll take a look at what is going on, but I wanted to put this issue in for tracking it since it's separate.

Start with the controller parameter parsing path that produces the reported "unable to find param definition" error when processing controller.go. Reproduce the issue with the Email type and Index action shown above, then verify that a named custom type can be accepted as an action input without the parser error.

Written by the indexing model from the issue text.